San Miguel - Areias Swell Statistics, All Year: Surf with Light or Offshore Winds
This image shows only the swells directed at San Miguel - Areias that coincided with light winds or offshore conditions through a typical year. It is based on 28044 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow show increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the most common swell direction, shown by the largest spokes, was NNW, whereas the the dominant wind blows from the WNW. The chart at the bottom shows the same thing but without direction information. For example, swells larger than 1.5 feet (0.5m) coincided with good wind conditions 19% of the time, equivalent to 69 days. Expect open water swells to exceed >3m (>10ft) 1.4% of the time (5 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that San Miguel - Areias is slightly protected from open water swells, we think that that clean surf can be found at San Miguel - Areias about 19% of the time and that surf is blown out by onshore wind 41% of the time. This is means that we expect 219 days with waves in a typical year, of which 69 days should be clean enough to surf.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.